<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>html的常用标签</title>
</head>
<body>
  <h1>这是h1</h1>
  <h2>这是h2</h2>
  <h3>这是h3</h3>
  <hr/>
  <a href="http://www.baidu.com" title="我要访问百度" target="_blank">访问百度</a><br>
  <a href="01_hello.html">访问html</a>
  <a href="01/test01.html">test01</a>
</body>
</html>